1. Field of the Invention
This invention relates to a stretchable, resilient pressure wrapping tape and method of application, the wrapping tape includes a gauge which indicates the amount of stretch of the tape applied during application. More particularly, the gauge includes a plurality of impressions printed upon the tape which assume a first appearance with the tape unstretched and a second appearance when the tape is stretched the proper amount for the desired application.
2. Description of the Prior Art
In both the utility and communication industries it is often necessary to form a splice between the distal ends of two wires. Such a splice might be formed by a simple twisted connection between two single strand wires, or the wire splice may incorporate a modular connector which joins the distal ends of multi-stranded wires, such as 25 pair communication wire. In any event, methods and apparatus are well known for operatively connecting the ends of two wires to form an effective splice.
When such a splice is formed, it is important that the splice and surrounding wire be protected from deterioration. Where the wire and splice is buried, such deterioration might result from moisture or the sometimes the caustic environment of the surrounding earth. In aerial applications, such deterioration may result from moisture collecting in the splice and inside the wire insulation surrounding the strands. In either event, if the deterioration is not combated, splice failure is the inevitable result.
In a recent development, a specialized type of protective pressure tape has been devised which when wrapped around such a splice and the adjoining wire significantly reduces the effects of deterioration. Generally speaking, the pressure tape is clear and self-adherent and is made from a plasticized polyvinyl chloride material. Preferably, such a tape has a tensile strength and resiliency such that the tape can be stretched at least 100% while retaining a large portion of its resiliency and tensile strength. In the context of the present application, "resiliency" is taken as meaning the tendency to resume its original shape when stretched.
Typically, such pressure wrapping tape is used in conjunction with a protective modular connector and other methods of protecting the splice from deterioration. In this case, the tape is normally applied as a final step in protecting the wire splice. The tape is stretchingly wrapped around the wire splice in a spiral or overlapping relation. Particularly in aerial applications where moisture has a tendency to collect inside the insulating sheathing, the pressure tape is wrapped not only around the wire splice but also around a portion of the adjoining wire. The compression induced by the pressure tape tends to dispel any pockets or voids in the splice and surrounding wire which might serve as collection points for moisture.
Because of the importance of correctly applying such pressure wrapping tape around a wire splice and the adjoining wire, exact specifications have been devised for the amount of compression to be developed by the pressure tape. If a splice fails, the failed splice is carefully examined to determine whether or not the proper specifications were followed during installation. The amount of compression developed by the pressure tape is a function of many factors, but of critical importance is the amount of elongation or stretch imparted to the tape during the wrapping of the wire.
Particularly in field conditions, it is difficult to effectively judge the amount of longitudinal stretch applied to the tape during the wrapping process. However, small differences in the amount of stretch can result in large differences in the amount of compressive force developed. If the amount of stretch is too small, the desired amount of compressive force is not developed and the wire splice and surrounding wire is not adequately protected. If the amount of stretch is too great, the tensile strength of the tape may be exceeded (breaking the tape), or the resilient properties of the tape can be diminished, whereupon the tape does not develop the desired amount of compressive force. Thus, it would be a significant advance in the art if an improved pressure tape were devised which incorporated a mechanism for ascertaining when the proper amount of stretch or elongation is applied to the tape during field installation.